Geological Map of the Knoxville District. Clear Lake Region.

1887

Becker, George F.

1:15k

Clear Lake West

1972

1:24k

Ventura Heights

1972

1:24k

Map of Cerro Gordo County, State of Iowa.

1875

Andreas, A. T. (Alfred Theodore), 1839-1900

1:127k

Mason City

1985

1:100k

Mason City

1985

1:100k

Mason City

1958

1:250k

Mason City

1954

1:250k

Mason City

1954

1:250k

Iowa.

1846

Mitchell, Samuel Augustus

1:1m